coinstats: Extract hash_type in-member to in-param

Currently, CCoinsStats is a struct with both in-params and out-params
where the hash_type and index_requested members are the only in-params.

This change removes CCoinsStats' hash_type in-param member and adds it
to the relevant functions instead.

[META] In subsequent commits, all of CCoinsStats' members which serve as
       in-params will be moved out so as to make CCoinsStats a pure
       out-param struct.

5 files changed, 19 insertions, 24 deletions

diff --git a/src/node/coinstats.cpp b/src/node/coinstats.cpp
index eed43a1bc7..8d94e1bd36 100644
--- a/src/node/coinstats.cpp
+++ b/src/node/coinstats.cpp
@@ -93,7 +93,7 @@ static void ApplyStats(CCoinsStats& stats, const uint256& hash, const std::map<u
 
 //! Calculate statistics about the unspent transaction output set
 template <typename T>
-static bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats& stats, T hash_obj, const std::function<void()>& interruption_point, const CBlockIndex* pindex)
+static bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats& stats, T hash_obj, const std::function<void()>& interruption_point, const CBlockIndex* pindex, CoinStatsHashType& hash_type)
 {
     std::unique_ptr<CCoinsViewCursor> pcursor(view->Cursor());
     assert(pcursor);
@@ -106,7 +106,7 @@ static bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats&
     stats.hashBlock = pindex->GetBlockHash();
 
     // Use CoinStatsIndex if it is requested and available and a hash_type of Muhash or None was requested
-    if ((stats.m_hash_type == CoinStatsHashType::MUHASH || stats.m_hash_type == CoinStatsHashType::NONE) && g_coin_stats_index && stats.index_requested) {
+    if ((hash_type == CoinStatsHashType::MUHASH || hash_type == CoinStatsHashType::NONE) && g_coin_stats_index && stats.index_requested) {
         stats.index_used = true;
         return g_coin_stats_index->LookUpStats(pindex, stats);
     }
@@ -144,19 +144,19 @@ static bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats&
     return true;
 }
 
-bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats& stats, const std::function<void()>& interruption_point, const CBlockIndex* pindex)
+bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats& stats, CoinStatsHashType hash_type, const std::function<void()>& interruption_point, const CBlockIndex* pindex)
 {
-    switch (stats.m_hash_type) {
+    switch (hash_type) {
     case(CoinStatsHashType::HASH_SERIALIZED): {
         CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
-        return GetUTXOStats(view, blockman, stats, ss, interruption_point, pindex);
+        return GetUTXOStats(view, blockman, stats, ss, interruption_point, pindex, hash_type);
     }
     case(CoinStatsHashType::MUHASH): {
         MuHash3072 muhash;
-        return GetUTXOStats(view, blockman, stats, muhash, interruption_point, pindex);
+        return GetUTXOStats(view, blockman, stats, muhash, interruption_point, pindex, hash_type);
     }
     case(CoinStatsHashType::NONE): {
-        return GetUTXOStats(view, blockman, stats, nullptr, interruption_point, pindex);
+        return GetUTXOStats(view, blockman, stats, nullptr, interruption_point, pindex, hash_type);
     }
     } // no default case, so the compiler can warn about missing cases
     assert(false);
diff --git a/src/node/coinstats.h b/src/node/coinstats.h
index aa771b18b0..ee3f3b0030 100644
--- a/src/node/coinstats.h
+++ b/src/node/coinstats.h
@@ -28,9 +28,6 @@ enum class CoinStatsHashType {
 };
 
 struct CCoinsStats {
-    //! Which hash type to use
-    const CoinStatsHashType m_hash_type;
-
     int nHeight{0};
     uint256 hashBlock{};
     uint64_t nTransactions{0};
@@ -69,12 +66,10 @@ struct CCoinsStats {
     CAmount total_unspendables_scripts{0};
     //! Total cumulative amount of coins lost due to unclaimed miner rewards up to and including this block
     CAmount total_unspendables_unclaimed_rewards{0};
-
-    CCoinsStats(CoinStatsHashType hash_type) : m_hash_type(hash_type) {}
 };
 
 //! Calculate statistics about the unspent transaction output set
-bool GetUTXOStats(CCoinsView* view, node::BlockManager& blockman, CCoinsStats& stats, const std::function<void()>& interruption_point = {}, const CBlockIndex* pindex = nullptr);
+bool GetUTXOStats(CCoinsView* view, node::BlockManager& blockman, CCoinsStats& stats, CoinStatsHashType hash_type, const std::function<void()>& interruption_point = {}, const CBlockIndex* pindex = nullptr);
 
 uint64_t GetBogoSize(const CScript& script_pub_key);
 
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 0a9458c276..3411f72a2c 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -862,7 +862,7 @@ static RPCHelpMan gettxoutsetinfo()
 
     const CBlockIndex* pindex{nullptr};
     const CoinStatsHashType hash_type{request.params[0].isNull() ? CoinStatsHashType::HASH_SERIALIZED : ParseHashType(request.params[0].get_str())};
-    CCoinsStats stats{hash_type};
+    CCoinsStats stats{};
     stats.index_requested = request.params[2].isNull() || request.params[2].get_bool();
 
     NodeContext& node = EnsureAnyNodeContext(request.context);
@@ -884,7 +884,7 @@ static RPCHelpMan gettxoutsetinfo()
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Querying specific block heights requires coinstatsindex");
         }
 
-        if (stats.m_hash_type == CoinStatsHashType::HASH_SERIALIZED) {
+        if (hash_type == CoinStatsHashType::HASH_SERIALIZED) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "hash_serialized_2 hash type cannot be queried for a specific block");
         }
 
@@ -903,7 +903,7 @@ static RPCHelpMan gettxoutsetinfo()
         }
     }
 
-    if (GetUTXOStats(coins_view, *blockman, stats, node.rpc_interruption_point, pindex)) {
+    if (GetUTXOStats(coins_view, *blockman, stats, hash_type, node.rpc_interruption_point, pindex)) {
         ret.pushKV("height", (int64_t)stats.nHeight);
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
         ret.pushKV("txouts", (int64_t)stats.nTransactionOutputs);
@@ -922,10 +922,10 @@ static RPCHelpMan gettxoutsetinfo()
         } else {
             ret.pushKV("total_unspendable_amount", ValueFromAmount(stats.total_unspendable_amount));
 
-            CCoinsStats prev_stats{hash_type};
+            CCoinsStats prev_stats{};
 
             if (pindex->nHeight > 0) {
-                GetUTXOStats(coins_view, *blockman, prev_stats, node.rpc_interruption_point, pindex->pprev);
+                GetUTXOStats(coins_view, *blockman, prev_stats, hash_type, node.rpc_interruption_point, pindex->pprev);
             }
 
             UniValue block_info(UniValue::VOBJ);
@@ -2285,7 +2285,7 @@ UniValue CreateUTXOSnapshot(
     const fs::path& temppath)
 {
     std::unique_ptr<CCoinsViewCursor> pcursor;
-    CCoinsStats stats{CoinStatsHashType::HASH_SERIALIZED};
+    CCoinsStats stats{};
     const CBlockIndex* tip;
 
     {
@@ -2305,7 +2305,7 @@ UniValue CreateUTXOSnapshot(
 
         chainstate.ForceFlushStateToDisk();
 
-        if (!GetUTXOStats(&chainstate.CoinsDB(), chainstate.m_blockman, stats, node.rpc_interruption_point)) {
+        if (!GetUTXOStats(&chainstate.CoinsDB(), chainstate.m_blockman, stats, CoinStatsHashType::HASH_SERIALIZED, node.rpc_interruption_point)) {
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
         }
 
diff --git a/src/test/coinstatsindex_tests.cpp b/src/test/coinstatsindex_tests.cpp
index 5b73481bc1..d7d09fa168 100644
--- a/src/test/coinstatsindex_tests.cpp
+++ b/src/test/coinstatsindex_tests.cpp
@@ -33,7 +33,7 @@ BOOST_FIXTURE_TEST_CASE(coinstatsindex_initial_sync, TestChain100Setup)
 {
     CoinStatsIndex coin_stats_index{1 << 20, true};
 
-    CCoinsStats coin_stats{CoinStatsHashType::MUHASH};
+    CCoinsStats coin_stats{};
     const CBlockIndex* block_index;
     {
         LOCK(cs_main);
@@ -69,7 +69,7 @@ BOOST_FIXTURE_TEST_CASE(coinstatsindex_initial_sync, TestChain100Setup)
     // Let the CoinStatsIndex to catch up again.
     BOOST_CHECK(coin_stats_index.BlockUntilSyncedToCurrentChain());
 
-    CCoinsStats new_coin_stats{CoinStatsHashType::MUHASH};
+    CCoinsStats new_coin_stats{};
     const CBlockIndex* new_block_index;
     {
         LOCK(cs_main);
diff --git a/src/validation.cpp b/src/validation.cpp
index a54ec8269e..5fdf0398df 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -5095,14 +5095,14 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
 
     assert(coins_cache.GetBestBlock() == base_blockhash);
 
-    CCoinsStats stats{CoinStatsHashType::HASH_SERIALIZED};
+    CCoinsStats stats{};
     auto breakpoint_fnc = [] { /* TODO insert breakpoint here? */ };
 
     // As above, okay to immediately release cs_main here since no other context knows
     // about the snapshot_chainstate.
     CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
 
-    if (!GetUTXOStats(snapshot_coinsdb, m_blockman, stats, breakpoint_fnc)) {
+    if (!GetUTXOStats(snapshot_coinsdb, m_blockman, stats, CoinStatsHashType::HASH_SERIALIZED, breakpoint_fnc)) {
         LogPrintf("[snapshot] failed to generate coins stats\n");
         return false;
     }